When you log into your Auctiva account, in the upper right side there is a box that says "Events". There should be numbers with 3 colors, green, orange and red. If there are any red numbers, that indicated postings with errors. Click on the red number and see what the errors are.
You might want to open a support case with Auctiva Support also. You will get the quickest help that way.
http://www.auctiva.com/help/requesthelp.aspx